The popularity of the Internet, a well-known, global network of cooperative interconnected computer networks, combined with the widespread availability of low-cost broadband networking and advanced digital compression techniques, has spurred the growth of what is known as interactive television. Interactive television provides viewers with compelling Internet and video content on their home television equipped only with a simple internet-television terminal, such as those pioneered by WebTV Networks, Inc. WebTV terminals are akin to the set-top boxes associated with a cable television network, and work in conjunction with a standard home television set to display both Internet and traditional television content, so that persons without access to a personal computer are able to access the Internet.
The ability to combine video content with the interactive features of interactive television has spawned numerous providers of video-on-demand applications for interactive entertainment systems. Currently, the typical video-on-demand application for interactive television consists of plural video-on-demand clients on terminals attached to the viewer's home television, and one or more video-on-demand servers connected to the video head-end. The user interface of current video-on-demand applications is contained entirely in the video-on-demand client, and provides commands to the video-on-demand server to select, start or stop and pay for the video played on the viewer's home television. Typically, the video-on-demand server provides access to the video content available for transmission, whereas the client controls the selection of the video and the payment mechanism.
There are several different brands of video-on-demand applications available on the market today. Three examples are Seachange, Vivid and Microsoft's Netshow Theater. In view of the popularity of the video-on-demand feature of interactive television, there will likely be many more video-on-demand servers developed in the near future.
One of the difficulties with the proliferation of competing video-on-demand applications is the lack of an industry standard communications protocol. The protocol controls the communication between the video-on-demand server and the various video-on-demand clients on the interactive television network. The challenge in a video-on-demand application is that it must be capable of managing not only the download of digital video data to the client, but also the transmission of control data to and from the client relating to system administration (e.g. channel assignment data, billing information, etc.).
Currently, most video-on-demand servers use a proprietary communications protocol unique to that video-on-demand server. Problems arise when the protocols used to control the video-on-demand servers aren't understood (are incompatible with) the protocols supported by the various video-on-demand clients. Examples of some of the diverse protocols in use today are DAVEC (a cable modem standard), DSMTC (used by certain video head-ends), and RTSP (an industry-proposed standard that has met with little success). The use of incompatible protocols has limited expansion options available to existing video on demand systems.
Moreover, the current configuration of most interactive video systems provide incomplete failover recoverability since the back-end servers on which most video-on-demand servers reside necessarily cannot completely manage their own failure.
Current video-on-demand servers use a limiting “segmented channel” model to transmit the video data. Under this model, each viewer is assigned a dedicated video channel. This greatly limits flexibility and expansion options.
Various embodiments of the present invention redress these and other shortcomings of the prior art by interposing a middle tier in the interactive video system. This middle tier—commonly a proxy server—provides various services, including protocol translation, system administration (dynamic channel assignment, load distribution, and failover), dynamic error-patching, and security.
According to one aspect, the invention provides an improved system and method for delivering a video-on-demand feature to remote clients of an interactive television network. The system and method employ the proxy server to reconfigure the components of a video-on-demand application into a flexible multi-tiered configuration, and to redistribute the functions of those components to the proxy server so as to enhance the performance, reliability, security, scalability and other features of the system.
One implementation of the present invention includes one or more proxy servers interposed between one or more video-on-demand servers and one or more video-on-demand clients. The proxy server includes a protocol translation component, a user interface component, a channel management component, a loadsharing component, a failover component and a security component.
The translation component translates, if necessary, the communication protocols used by the video-on-demand server and video-on-demand client, and fixes—on-the-fly—certain errors in those protocols. The user interface component distributes the user interface between the video-on-demand server and video-on-demand client and provides user interface enhancements. The channel management component manages the assignment of transmission channels to video-on-demand clients. The failover component redirects requests to failed video-on-demand servers to secondary/alternate servers. The loadsharing component manages the load between the video-on-demand servers and possibly one or more other proxy servers in a given server configuration of the interactive television network at the head-end. The security component provides a uniform security framework that previously was located in each individual video-on-demand server at the head-end.
In one implementation of the method and system, a promotional component is also provided to initiate delivery of customized promotional content from the proxy server to the video-on-demand client.
The foregoing and other features and advantages of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.